Product pressurized air dispenser having improved product control valve actuator

ABSTRACT

An improved fluent product dispenser in which the product is dispensed by means of compressed air has a dispenser body having a dispensing means therein for mixing and dispersing the fluent product and compressed air and has a piston-cylinder means thereon by which the air is compressed, and when it reaches a certain predetermined pressure, is suddenly released. The fixed member of the piston-cylinder means has a fluent product containing recess opening toward the movable member of the piston-cylinder means, and a product pressurizing piston in the product containing recess has an end exposed toward the movable member or the piston-cylinder means. A product control valve means controls the flow of product from the product containing recess to the dispensing nozzle through the body. Likewise, a compressed air valve opens to permit flow of compressed air through a compressed air path in the body to the nozzle when the compressed air reaches a certain predetermined pressure. A product valve actuator is coupled to the product valve and is mounted in a flexible diaphragm sealed at the edge thereof, and the compressed air flow path opens into the space beneath the diaphragm so as to open the product valve in a predetermined time relationship to the opening of the compressed air valve means, so that when the movable member of the piston-cylinder means is moved toward the fixed member for compressed air, the compressed air acts on the product pressurizing piston for pressurizing the product, and when the compressed air is released from the piston-cylinder means, it acts on the product valve actuator to actuate the product valve and release the product only upon release of compressed air.

This application is a continuation-in-part of copending application Ser.No. 520,946 filed Nov. 4, 1974, now U.S. Pat. No. 3,910,465.

This invention relates to a dispenser for dispensing a fine spray of afluent product by means of compressed air, and more particularly relatesto an improved product control valve actuator for such a dispenser inwhich the product to be dispensed is pressurized and mixed with thecompressed air in the nozzle to create a fine spray with a good patternof droplets and a relatively large proportion of the spray beingdroplets of extremely fine size.

BACKGROUND AND PRIOR ART

Recent developments in the aerosol dispenser art have been along thelines of providing a dispenser in which the fluent product is dispensedby means of compressed air, rather than by one of the conventionalpropellants, such as Freon or the like. The toxic properties of Freonhave been a subject of concern, and the development of compressed airtype dispensers avoids the use of Freon, thus avoiding the problemsassociated therewith.

Recently developed dispensers which use a charge of compressed air toaspirate a product from a separate product container each time thedispenser is actuated are found in U.S. Pat. Nos. 3,672,545 and3,733,010. However, these dispensers do not produce a spray withdroplets of a size thought to be desirable for a medicament containinginhalent. Thus, in U.S. Pat. Application Ser. No. 411,267, nowabandoned, filed Oct. 31, 1973 in the name of Roger B. Caron et al.,there is disclosed a dispenser in which fine droplets on the order ofone to ten microns can be generated in such a compressed air typedispenser by exerting a pressure on the product. Droplets of this sizeare thought to be most effective for an inhalent.

However, the apparatus of this lastmentioned application for generatingthe charge of compressed air and exerting a pressure on the product atthe time of the release of the compressed air so as to dispense theproduct is somewhat complicated. Thus far, it has been the practice toexert this pressure on the product by means of mechanical actuation of apiston in contact with the product by a mechanical connection betweenthe compressed air compressing means and the piston, or to exert apressure on the product by means of the force exerted by the hand of theuser of the dispenser directly on the product through the container forthe product.

The type of dispenser in which pressure is exerted on the fluent productby means of a product pressurizing piston mechanically actuated by thecompressed air means is somewhat complex in structure, requiring anumber of parts and rather complicated shapes of parts, which aredifficult to mold, such as in a material like plastic. The type ofdispenser in which the pressure is exerted on the product by the forceexerted by the hand of the user can be made in a somewhat lesscomplicated manner, but again a number of parts are necessary, and thepressure is not always properly coordinated with the pressure exerted onthe means for compressing the air.

Further, the structure of these devices does not lend itself readily toeasily controlling the relative pressure of the compressed air chargerelative to the pressurized product.

It is desirable to have such a device which has a simple construction,i.e. relatively few parts, and a structure which makes it possible toshape the parts in relatively simple shapes so that they are easilymolded on conventional molding apparatus. It is further desirable tohave such a structure in which the relative pressures of the compressedair and the pressurized product at the nozzle where they are mixed canbe easily controlled by varying the structural features of the device.Technical progress in the art of such aerosol dispensers would beachieved if such a device could be provided.

OBJECTS AND SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide adispensing device for dispensing fluent material by means of a charge ofcompressed air, in which the fluent material is also pressurized and thepressurized product and compressed air are mixed at a dispensing nozzle,and which structure has relatively few parts, which parts, particulaly aproduct control valve actuator, are easily molded in plastic onconventional apparatus, and which parts are easily assembled into thefinal device.

More particularly, it is the object of the present invention to providesuch a dispenser in which the product control valve actuator is not onlyreadily responsive to the pressure of the compressed air, but also iseasily sealed to the dispenser structure to prevent escape of compressedair.

These objects are achieved by a dispenser in which a dispenser bodyhaving a dispensing means therein for mixing and dispersing the fluentproduct and compressed air has a piston-cylinder means thereon by whichthe air is compressed, and when it reaches a certain predeterminedpressure, is suddenly released. The fixed member of the piston-cylindermeans has a fluent product containing recess opening toward the movablemember of the piston-cylinder means, and a product pressurizing pistonin the product containing recess has an end exposed toward the movablemember or the piston-cylinder means. A product control valve meanscontrols the flow of product from the product containing recess to thedispensing nozzle through the body. Likewise, a compressed air valveopens to permit flow of compressed air through a compressed air path inthe body to the nozzle when the compressed air reaches a certainpredetermined pressure. A product valve actuator is coupled to theproduct valve and is mounted in a flexible diaphragm sealed at the endthereof to the body. The compressed air path opens into the spacebeneath the diaphragm so as to open the product valve in a predeterminedtimed relationship to the opening of the compressed air valve means inresponse to the pressure of the compressed air flowing in the path whenit is released from the piston-cylinder means, so that when the movablemember of the piston-cylinder means is moved toward the fixed member forcompressing air, the compressed air acts on the product pressurizingpiston for pressurizing the product as well as to actuate the productvalve and release the product only upon release of compressed air.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail hereinafter inconnection with the accompanying drawings, in which:

FIG. 1 is a sectional elevation of a first embodiment of the dispensingdevice according to the present invention, with the parts in positionsat the start of a dispensing operation;

FIG. 2 is a view similar to FIG. 1 with the parts in positions at theend of a dispensing operation;

FIG. 3 is a sectional view similar to FIG. 1 of a modified embodiment ofthe dispensing device; and

FIG. 4 is a sectional view of the improved product valve actuator.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIGS. 1 and 2, the dispenser shown therein has a body10 having a dispensing nozzle means 11 therein. This dispensing nozzlemeans is constituted by a nozzle insert 12 having a smaller diameterinner portion 13 fitted tightly in a smaller diameter recess 14 which isat the bottom of a larger diameter recess 15 opening laterally from thebody 10. The nozzle insert 12 has a central Venturi passage 12a andlateral passages 12b. It further has larger diameter portion 16 whichfits into the larger diameter recess 15. The inner end of the largerdiameter portion 16 is beveled at 17 so as to leave a compressed airsupply chamber 18 around the inner end of the larger diameter portion 16at the inner end of the larger diameter recess 15.

A piston-cylinder means depends from the body 10 and has a fixed member19 which in the present embodiment constitutes a piston member, and amovable member 20, which in the present embodiment constitutes acylinder member slidable over the piston member 19. A gasket 21 fittedinto a groove 22 in the inner surface of the piston 20 at the open endthereof slides along the outer surface of the piston member 19 to sealthe joint between the piston 19 and the cylinder 20. Movement of thepiston-cylinder member 20 toward the piston member 19 compresses air inthe space 23 within the cylinder member 10.

The fixed member of the piston-cylinder means, i.e. the piston member19, has a product containing recess 24 therein which opens toward themovable member, i.e. the cylinder member 20. A product pressurizingpiston 25 is slidably positioned in the recess 24, and a gasket 26 in agroove 27 in the upper end of the piston 25 seals the piston against theinner wall of the product containing recess 24.

An air return valve is provided at the bottom of the cylinder member 20,and is constituted by a resilient flap 28 held in the closed end of thecylinder member 20 by a pin 29 and covering an air inlet 30. It ispreferred that a lateral air inlet passage 31 be provided extending fromthe air inlet 30 laterally thereof and opening out of the side of thecylinder member 20 so that air return to the interior of the cylindermember 20 will take place even if the finger of a user shouldaccidentally cover the outer end of the air inlet passage 30.

Opening out of the inner end of the product containing recess 24 andextending through the body 10 is a cylindrical bore 32, and extendinglaterally from the cylindrical bore 32 and opening into the bottom ofthe smaller diameter recess 14 is a lateral passage 33. The cylindricalbore 32 and the lateral passage 33 together constitute a product flowpath through the body 10 from the product containing recess 24 to thenozzle means 11.

A product control valve means is provided in the cylindrical bore 32,and is constituted by a pin 34 having at least one cylindrical groove 34therein in which is a sealing gasket 36 which slides along the wall ofthe bore 32 to seal the bore 32. The pin 34 is movable in the axialdirection of the bore 32 so that the gasket 36 slides between a positionwhich is located between the product containing recess 24 and thelateral passage 33, and a position in which the gasket 36 is past thelateral passage 33 in a direction away from the product containingrecess 24. Thus, movement of the pin 34 in a direction away from theproduct containing recess 24 opens the product flow path from theproduct containing recess 24 to the nozzle means 12. In the actualembodiment shown, there are two ring gaskets around pin 34 so that thepin is guided linearly along bore 32. Alternatively, the pin 34 andgaskets can be cast as a single plastic element with annular projectionsthereon which slide in sealing relationship along the bore 32, as shownin FIG. 4.

The body 10 further has a compressed air flow path therethrough in theform of a bore 37 which opens out of the larger diameter recess 15 fromthe compressed air supply chamber 18. The bore 37 extends within thewall of the piston member 19 and opens laterally thereof. It willtherefore be seen that the movement of the gasket 21 past the opening ofthe bore 37 as the cylinder member 20 moves along the piston member 18acts as a valve to release the compressed air from within the cylindermember 20 into the compressed flow path 37.

A product valve actuator is connected to the product control valve. Theend of the body 10 remote from the piston-cylinder means has anupstanding collar 38 thereon spaced inwardly from the exteriorperipheral surface of the body 10 to leave a ledge 38a. Within the space39 defined by the collar, into which the bore 32 opens is positioned aproduct valve actuator generally indicated at 40, which has an actuatorelement 40a which is connected to the end of the pin 34 remote from theproduct containing recess 24. Projecting radially outwardly and upwardlyfrom actuator element 40a is a flexible diaphragm 40b and at theperipheral edge of diaphragm 40b is an annular flange 40c having anannular projection 40d on the upper edge thereof. The lower edge offlange 40c is seated on ledge 38a and against the outside of collar 38.A cover 41 vented at 41a is fitted tightly over the outside of body 10.A seat 41b on the inside of the cover engages the annular projection 40dto seal thereagainst and urge flange 40c firmly against ledge 38a.Depending from the center of the cover 41 is a projection 42 aroundwhich is a spring 43. The lower end of spring 43 is around actuatorelement 40a and urges actuator 40 downwardly, i.e. toward the closedposition of product control valve. A compressed air passage 44 extendsfrom the compressed air chamber 18 through the body 10 into the space39, and opens into the space beneath the diaphragm 40b.

With the parts in the positions shown in FIG. 1, it will be understoodthat fluent product within the product containing recess 24 is atatmospheric pressure, as is any air the space 23 within the cylindermember 20. There is thus little tendency for product to leak from theapparatus, since it is under no pressure.

Force is exerted on the opposite ends of the dispenser, i.e. on thelower end of the cylinder member 20 and the upper end of the cover 41,as shown in FIG. 1. This will cause the cylinder member 20 to slideupwardly along the piston member 19, compressing air in the space 23.This air will be under increasing pressure, and will exert pressure onthe product pressurizing piston 25. The spring 43, however, issufficiently strong to hold the actuator 40 tightly against the bottomof the space 39 within the collar 38 against the force caused bypressure of the product on the bottom of pin 34, thus holding theproduct control valve closed, i.e. holding the pin 34 with the gasket 36between the product containing recess 24 and the lateral passage 23.

When the gasket 21 within the cylinder member 20 passes the lateralopening of the compressed air bore 37, however, compressed air at apredetermined pressure will be released suddenly into the compressed airflow path, and will reach the compressed air supply chamber 18 aroundthe nozzle insert 12. It will further flow through the passage 44 andact on the bottom of the diaphragm 40b. The area of the bottom ofdiaphragm 40b is sufficiently large so that the pressure of the airthereon raises the actuator 40 against the action of the spring 43,thus, moving the gasket 36 upwardly in the bore 32 past the lateralpassage 33. Product under pressure is therefore caused to flow throughthe bore 32 and lateral passage 33 into the central passage 12a of thenozzle insert 12. In the meantime, compressed air is already flowingthrough the lateral passages 12b of the nozzle into the central passage12a thereof. Compressed air and pressurized products are thus mixed inthe central passage of the nozzle insert 12, and are dispensed laterallyof the device.

As the cylinder member 20 continues to move upwardly, it continues tocompress the air somewhat within the space 23 to compensate to a certaindegree for the escape of air through the compressed air flow path 37.Thus, compressed air at the maximum pressure will continue to flow for ashort time after the opening of the valve means for the compressed air.The cylinder member 20 eventually reaches the position shown in FIG. 2in which it abuts the underside of the body 10, at which point nofurther air is compressed. The pressure of the air within the space 23then drops rapidly until it again reaches atmospheric.

When the pressure of the air begins to drop, the pressure beneath theactuator 40 falls, and the spring 43 pushes the actuator and the pin 34downwardly, thus closing the product control valve by moving the gasket36 toward the product containing recess 24 past the lateral passage 33.However, compressed air will continue to flow, at a reduced pressure,beyond this time, thus cleaning from the nozzle insert 12 any productremaining therein.

When the air has been exhausted from the space 23, the cylinder member20 is drawn downwardly, in FIG. 1, and air flows into the space 23 pastthe air return valve by lifting the flap 28. The device is then readyfor reuse.

By changing the position of the lateral opening from the compressed airbore 37, the pressure at which the compressed air is released can bevaried. The farther from the outer end of the piston member 19 is theopening, the higher the pressure at which the air will be released.

As seen in FIG. 3, the device can be modified so as to provide thecompressed air flow path through a bore 37a located, for convenience inmanufacturing, on the opposite side of the device from the dispensingnozzle means 11. In this case, the bore 37a extends directly into thespace beneath diaphragm 40b. Further the passage 44a from the space 39into the compressed air supply chamber 18 is positioned immediatelyabove the larger recess portion 15, in the illustrated arrangement in aposition generally diametrally opposite in the space 39 to the point atwhich the bore 37a opens into space 39.

With this arrangement, by simply varying the size of the passage 44a,the pressure of the compressed air at the dispensing nozzle means 11 canbe controlled so as to produce the ratio of air pressure to productpressure which is best for atomizing. The smaller the bore, the lowerthe pressure of the air at the nozzle. In addition, the hole size timesthe product flow and is thus the main way of controlling the dosagedispensed by the device. This also makes it possible to use the full airpressure to actuate the product control valve in a positive manner,while using the same air to provide air at a lower pressure to thedispensing nozzle means. The upwardly angled configuration of thediaphragm insures that the actuator 40 will respond immediately to thepresence of air under pressure in the space therebeneath. Moreover, theflange 40c with the projection 40d is held tightly between the cover 41and body 10, thereby sealing the space beneath the diaphragm, yetpermitting free movement of element 40a and hence of the product controlvalve. This is accomplished with a single element easily molded of arelatively soft plastic such as polypropylene, and easily inserted intothe device during assembly. The overall device is therefore simplifiedand the cost reduced.

Many modifications of the construction are possible. For example, themember 19 could be extended to serve as a cylinder member, and a solidpiston member could be provided to slide within it. A branch passagecould be provided, in the embodiment of FIG. 3, from the bore 37a to thecompressed air supply chamber 18, rather than from the groove 39a, tothe chamber 18.

It will be seen that there has thus been provided a dispenser whichdispenses the product by means of a charge of compressed air which iscreated each time the device is actuated, yet in which the compressedair also serves to exert the pressure to pressurize the product. Thedevice is quite simple, consisting of only a dozen or so parts, some ofwhich are readily available, such as the gaskets 21 and 26 and 36, andthe spring 43, and the remainder of which are easily molded onconventional plastic molding machinery. The device can thus be made at alow cost, yet is reliable in operation, and produces a spray of veryfine droplets on the order of one to ten microns in size, with a gooddistribution of the droplets size in the spray and a good spray pattern.

In addition, it will be seen that by the arrangement disclosed, thecompressed air starts flowing into the nozzle insert 12 just a veryshort time ahead of the arrival of the product, i.e. during a delay inwhich the compressed air reaches and lifts the actuator 40. However,because the compressed air pressure soon starts to fall and falls rathergradually, the product control valve closes before the end of the flowof the compressed air, so that the compressed air at the lower pressureat the end of the actuation of the device serves to clean the nozzleinsert of any product remaining therein. Moreover, because the openingof the compressed air bore 37 is below the maximum upper position of thecylinder member 20, the cylinder member continues to move and generatefurther compressed air, even after the initial release of the compressedair. This gives a short period of time during which the pressure of thecompressed air remains at a maximum, thus promoting good productdispersal.

It is thought that the invention and its advantages will be understoodfrom the foregoing description, and it is apparent that various changesmay be made in the form, construction and arrangement of the partswithout departing from the spirit and scope of the invention orsacrificing its material advantages, the forms hereinbefore describedand illustrated in the drawings being merely preferred embodimentsthereof.

What is claimed is:
 1. In a dispenser for dispensing a fine spray bymeans of compressed air and having a body having a dispensing nozzlemeans therein for mixing and dispensing a fluent product and compressedair, a piston-cylinder means depending from said body and having a fixedmember in said body and a movable member movable relative to said fixedmember for compressing air therebetween, said fixed member having afluent product containing recess therein opening toward said movablemember, a product pressurizing piston in said product containing recesshaving an end exposed toward said movable member, said body having aproduct flow path therethrough from said product containing recess tosaid nozzle means and a product control valve means in said product flowpath for controlling flow of product therethrough, and said body furtherhaving a compressed air flow path therethrough to said nozzle means andcompressed air valve means in said compressed air flow path which isopened near the end of the movement of said movable means for releasingcompressed air at a predetermined pressure into said compressed air flowpath, the improvement comprising:a product valve actuator having anactuator element coupled to said product valve, a flexible diaphragmextending outwardly from said actuator element and sealing means on theperiphery of said diaphragm fixed in sealing engagement to said body,said compressed air flow path opening beneath said diaphragm and saidproduct valve actuator being movable in response to the pressure of thecompressed air for opening said product valve, whereby when the movablemember is moved toward the fixed member for compressing air, thecompressed air acts on said product pressurizing piston for pressurizingthe product, the compressed air at a predetermined pressure is releasedto said flow path, said valve actuator is moved to open said productvalve.
 2. A dispenser as claimed in claim 1 in which said body has arecess in which said actuator element is positioned for movementrelative to said body, a cover over said recess, said diaphragm havingthe sealing means engaged between said body and said cover, and biasmeans between said cover and said actuator element acting on saidactuator element for urging said element in the direction for closingthe product control valve.
 3. A dispenser as claimed in claim 1 in whichsaid sealing means is a flange around the periphery of said diaphragmseated on said body around the edge of said recess, said flange having aprojection on the edge thereof facing away from said body, and said caphas a seat on the inside thereof pressing against said projection whensaid cap is in position on said body for urging said flange against saidseat and providing a seal between said projection and said seat.
 4. Adispenser as claimed in claim 1 in which said diaphragm is angled awayfrom said body as it extends outwardly from said actuator element toleave a space between said diaphragm and said body, said compressed airflow path opening into said space. .Iadd.
 5. In a dispenser head fordispensing a fine spray by means of compressed gas, said head having abody with a dispensing nozzle means therein for mixing and dispensing afluent product and compressed gas, said body having a product flow paththerethrough from one end thereof to said nozzle means and a productcontrol valve means in said product flow path for controlling flow ofproduct therethrough, said body further having a compressed gas flowpath therethrough from said one end thereof to said nozzle means, theimprovement comprising:a product valve actuator having an actuatorelement coupled to said product valve, a flexible diaphragm extendingoutwardly from said actuator element and sealing means on the peripheryof said diaphragm fixed in sealing engagement to said body, saidcompressed air flow path opening beneath said diaphragm and said productvalve actuator being movable in response to the pressure of thecompressed air for opening said product valve, whereby when compressedgas is caused to flow through said compressed gas flow path inconnection with the dispensing of fluent product, said valve actuator ismoved to open said product valve. .Iaddend.